Guest jeff1216 Posted November 16, 2003 Share Posted November 16, 2003 I am grasping for straws here. Just a reminder: 78 280Z removed the stock head, fuel injection,cpu, and wiring harness Mounted an E88 head Arizona intake Holley 390 For the 4th time......I pulled the the timing cover and chain off ( even bought a new timing set) Crank and cam are set on the money Dizzy is on the money firing order is on the money. I can get the car running but you have to pump the gas and keep the rpms high.........keeps kicking gas back thru the carb. All point to the timing being off.....BUT it is not! Here is my only thought.................. When I removed the wiring harness did I remove something to the ignition module? Does this car have an ignition module? Since I have the stock electronic dizzy did I need to run the 2 wires from the dizzy somewhere else after removing the comp.? When the 240 or 260 guys install a late model electronic dizzy on there car where do they run the 2 power wires to? Do they install an ignition module? Please give any suggestion that you can......I am all out of ideas. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 16, 2003 Share Posted November 16, 2003 Sorry to hear that you're still having problems. 2 things to suggest. 1. Check fuel pressure. I know that's been said before but I don't remember if you've done it. In fact, just go buy the Purolator fuel pressure regulator from the auto parts store. They're cheap. 2. If you still think it is timing related, check to see that your front crank pulley didn't spin. The outside timing marks and the inside pulley are connected with a strip of rubber. If the rubber cracks then the outside where the timing marks are can actually rotate on the pulley, making you time it to what seems like the right spot, but in actuality you can be way off. You can check by pulling #1 spark plug, sticking a pen or something in the hole, and turning the crank with a ratchet. Turn it to TDC, and make sure that it feels like TDC on the pen, like the pen stops moving up right before you get to TDC. If it has spun--GET A NEW HARMONIC BALANCER ASAP!!! Good luck. Jon Quote Link to comment Share on other sites More sharing options...
Mack Posted November 16, 2003 Share Posted November 16, 2003 is it possible that your dist. is 180 degrees out? thats messed me up on more than one occasion. If its backfiring, I would suspect that. McAdam Quote Link to comment Share on other sites More sharing options...
Guest jeff1216 Posted November 16, 2003 Share Posted November 16, 2003 In regards to this 180 out thing......If I put the motor at top dead center and my rotor is pointing at the #1 cylinder....isnt it impossible to be 180 out? Quote Link to comment Share on other sites More sharing options...
Guest jeff1216 Posted November 16, 2003 Share Posted November 16, 2003 Comp. results Less than 6 revolutions 180-190 per cylinder If you let it turn over and build max pressure it builds to and holds 230 to 235 psi What does that mean? Quote Link to comment Share on other sites More sharing options...
TimZ Posted November 16, 2003 Share Posted November 16, 2003 In regards to this 180 out thing......If I put the motor at top dead center and my rotor is pointing at the #1 cylinder....isnt it impossible to be 180 out? No, because you could be at TDC on either the exhaust or intake stroke. You need to look at the cam when you have it at TDC with the rotor pointing to #1. If both cam lobes for the #1 cylinder are pointing up (valves closed), then you are on the intake stroke and the dizzy is correct. If the lobes are pointing down (valves open) then you are 180 out. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted November 16, 2003 Share Posted November 16, 2003 Easiest way to check the distributor placement, is just to swap out the plug wies on the cap by 180*. Tim Quote Link to comment Share on other sites More sharing options...
Guest jeff1216 Posted November 16, 2003 Share Posted November 16, 2003 OK....here is where I am now. I can get the car to start a little easier.....still will not idle and you have to constantly feather the gas to keep it running (running very rough I might ad) One thing it has started to do..................While feathering the gas it will all of a sudden RACE to a very high RPM until the excess gas burns off......over and over....feather the gas....give it more gas let off the gas and she runs up to a high rpm from the previous gas pushing.....any ideas? Am I getting any closer??? Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted November 16, 2003 Share Posted November 16, 2003 Just my 2 cents, if you are having problems with it backfiring through the carb, I'd try finding the problem some other way than running the engine. If you keep messing with it while it is running, giving it more gas, or try changing the distributor 180* just to "try" then you are risking some serious trouble. I'd hate to find out that you blew something up. I nearly blew myself up with my truck when it was 180* out and I did not know and the explosion was enough to move the hood on my truck. (Hoods on 65 GMC trucks arent light). Keep the engine off while looking for the problem. With that being said... take the carb off of the intake and put it on a rag. Put fuel pressure to it via an electric pump and see if it starts soaking the rag. If it does, then you know that the carb is the problem. If it does not then report back on that and we can go from there. Feel free to email, PM, or IM me for more help. I have been through similar trouble with my truck and now my truck runs like a champ, lets get your Z doing the same. Quote Link to comment Share on other sites More sharing options...
Guest jeff1216 Posted November 16, 2003 Share Posted November 16, 2003 I thought the Holley would make things simpler.... LOL The valve timing will be done once more this week (not by choice) My 9 year old was holding the light and knocked a screw down into the timing cover. It does not get any better than this. I can only laugh at this point. HA HA Quote Link to comment Share on other sites More sharing options...
turbobluestreak Posted November 17, 2003 Share Posted November 17, 2003 kids, arn't they a joy. I'm not looking to forward to having them some day because of things like what just happened to you. I had this problem with my 81 turbo everyone kept telling me it was timing people on the boards and off the boards. Then to get my best friend to believe me I riped it all down and showed it. My problems turned out to be that I removed 6 casting plugs from the bottom of my intake to see what was under there. Causing my z to be extreamly lean. I know it's a long shot but is the carb good? If you've checked every that is reasonable start checking the whole set up. tbs Quote Link to comment Share on other sites More sharing options...
Guest Z-rific Posted November 17, 2003 Share Posted November 17, 2003 Just caught this on the V8 forum. First, I really don't think your dizzy is 180 out. It wouldn't run as long as it does with the dizzy in 180 out. It's sounding much more like a carb/intake/head deal to me. I've long forgotten the head info I used to know on L6's, so I'll leave that to someone else. I'm sure you checked the intake and exhaust manifolds to make sure they work/line up properly with the head. Okay, your 78 has a high pressure fuel pump. This is necessary for fuel injection. This can handle in excess of 20 psi. Your Holley carb can handle a maximum of about 9 psi. Did you change out the old fuel pump for a low pressure pump? If not, and you don't have a fuel pressure regulator with an excess line returning to the tank, your way overflooding that Holley. By the way, if in the futre, you don't use your stock fuel return line (which you shouldn't need with the carb) don't forget to plug that line good. If pressure builds in the system (which it will) it will force gas from the tank back through the return line. Quote Link to comment Share on other sites More sharing options...
tmujwid Posted November 18, 2003 Share Posted November 18, 2003 Yes, it has an electronic ignition module on the passenger side beneath the kick panel. My understanding from the Haynes manual is the thing has two power feeds. How much vacuum did it have when running, less than 12-15 inches indicates a leak. Quote Link to comment Share on other sites More sharing options...
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